The aim of this study is to determinate the influence of an alternative adhesive application protocol (i.e. consecutive application of an extra adhesive layer)on restoration longevity in primary molars.

After caries removal, enamel margins will be conditioned with phosphoric acid gel 37% by 15 seconds and dentin walls by 8 seconds. The etchant will be removed with use of water spray by 30 seconds. The water excess will be removed with a cotton pellet. The first layer of Prime & Bond 2.1 adhesive will be applied with a microbrush. After 20 seconds a second layer will be applied and after 20 seconds, the layers will be gently air-dried by 5 seconds. The two layers will be photopolymerized by 10 seconds with a LED photoactivation unit.

Active Comparator: Two adhesive coats

Consecutive application of two one-bottle adhesive coats

Procedure: Three adhesive coats

After caries removal, enamel margins will be conditioned with phosphoric acid gel 37% by 15 seconds and dentin walls by 8 seconds. The etchant will be removed with use of water spray by 30 seconds. The water excess will be removed with a cotton pellet. The first layer of Prime & Bond 2.1 adhesive will be applied with a microbrush. After 20 seconds a second layer will be applied and after a similar period a third layer will be applied over cavity walls. Again, after 20 seconds, the layers will be gently air-dried and photopolymerized by 10 seconds with a LED photoactivation unit.

Detailed Description:

Adhesive systems based on total etch technique remains the most popular products among dental practitioners. These systems are based on the use of an acid conditioner to remove the smear layer and demineralize the enamel and dentin. After the removal of the conditioner by rinsing, a mixture containing the primer and adhesive - i.e. one bottle adhesives - is applicated over the demineralized tissues. The polymerization of the adhesive monomers into microporosities created by acid conditioning forms the structure knowing as hybrid layer or resin-dentin interdifusion zone. A common problem related to total etch technique is the incomplete infiltration of adhesive monomers through demineralized dentin, resulting in the presence of a zone of unprotected collagen fibrils beneath the hybrid layer that is prone to enzymatic degradation. According to some laboratory studies, consecutive application of multiple adhesive coats results in quantitative and qualitative improvements in dental adhesion. In addition to increasing the values of bond strength to dentin, consecutive application of multiple adhesive layers enhances the infiltration of adehesive monomers through demineralized dentin, resulting in a more homogenous hybrid layer.

Eligibility

Ages Eligible for Study:

5 Years to 8 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

Yes

Criteria

Inclusion Criteria:

Presence of two or more pairs of caries lesions in occlusal or occluso-approximal surfaces of primary molars

Exclusion Criteria:

Systemic diseases in which dental treatment is a risk to patient's life

Bruxism

Orthodontic appliance

Absence of occlusal contact in eligible teeth

Signs and symptoms of pulp infflamation or necrosis

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT01680289